diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-21 11:21:19 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-21 11:21:19 -0700 |
commit | 43d451f163c1b615c1bedef95258c49712679eeb (patch) | |
tree | 52ed78b04435ffbd663a902bbd5bdb69a65ad584 /include | |
parent | 21d2271fd0812ebe3716cab0b48356837485a74d (diff) | |
parent | 9f3e3cacb2ffdefe28c7cf490bf543e4dcb2770a (diff) |
Merge branch 'mailbox-for-linus' of git://git.linaro.org/landing-teams/working/fujitsu/integration
Pull mailbox framework from Jassi Brar:
"A framework for Mailbox controllers and clients have been cooking for
more than a year now.
Everybody in the CC list had been copied on patchset revisions and
most of them have made sounds of approval, though just one concrete
Reviewed-by. The patchset has also been in linux-next for a couple of
weeks now and no conflict has been reported. The framework has the
backing of at least 5 platforms, though I can't say if/when they
upstream their drivers (some businesses have 'changed')"
(Further acked-by by Arnd Bergmann and Suman Anna in the pull request
thread)
* 'mailbox-for-linus' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
dt: mailbox: add generic bindings
doc: add documentation for mailbox framework
mailbox: Introduce framework for mailbox
mailbox: rename pl320-ipc specific mailbox.h
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/mailbox_client.h | 46 | ||||
-rw-r--r-- | include/linux/mailbox_controller.h | 133 | ||||
-rw-r--r-- | include/linux/pl320-ipc.h (renamed from include/linux/mailbox.h) | 0 |
3 files changed, 179 insertions, 0 deletions
diff --git a/include/linux/mailbox_client.h b/include/linux/mailbox_client.h new file mode 100644 index 00000000000..307d9cab202 --- /dev/null +++ b/include/linux/mailbox_client.h @@ -0,0 +1,46 @@ +/* + * Copyright (C) 2013-2014 Linaro Ltd. + * Author: Jassi Brar <jassisinghbrar@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef __MAILBOX_CLIENT_H +#define __MAILBOX_CLIENT_H + +#include <linux/of.h> +#include <linux/device.h> + +struct mbox_chan; + +/** + * struct mbox_client - User of a mailbox + * @dev: The client device + * @tx_block: If the mbox_send_message should block until data is + * transmitted. + * @tx_tout: Max block period in ms before TX is assumed failure + * @knows_txdone: If the client could run the TX state machine. Usually + * if the client receives some ACK packet for transmission. + * Unused if the controller already has TX_Done/RTR IRQ. + * @rx_callback: Atomic callback to provide client the data received + * @tx_done: Atomic callback to tell client of data transmission + */ +struct mbox_client { + struct device *dev; + bool tx_block; + unsigned long tx_tout; + bool knows_txdone; + + void (*rx_callback)(struct mbox_client *cl, void *mssg); + void (*tx_done)(struct mbox_client *cl, void *mssg, int r); +}; + +struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index); +int mbox_send_message(struct mbox_chan *chan, void *mssg); +void mbox_client_txdone(struct mbox_chan *chan, int r); /* atomic */ +bool mbox_client_peek_data(struct mbox_chan *chan); /* atomic */ +void mbox_free_channel(struct mbox_chan *chan); /* may sleep */ + +#endif /* __MAILBOX_CLIENT_H */ diff --git a/include/linux/mailbox_controller.h b/include/linux/mailbox_controller.h new file mode 100644 index 00000000000..d4cf96f07cf --- /dev/null +++ b/include/linux/mailbox_controller.h @@ -0,0 +1,133 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef __MAILBOX_CONTROLLER_H +#define __MAILBOX_CONTROLLER_H + +#include <linux/of.h> +#include <linux/types.h> +#include <linux/timer.h> +#include <linux/device.h> +#include <linux/completion.h> + +struct mbox_chan; + +/** + * struct mbox_chan_ops - methods to control mailbox channels + * @send_data: The API asks the MBOX controller driver, in atomic + * context try to transmit a message on the bus. Returns 0 if + * data is accepted for transmission, -EBUSY while rejecting + * if the remote hasn't yet read the last data sent. Actual + * transmission of data is reported by the controller via + * mbox_chan_txdone (if it has some TX ACK irq). It must not + * sleep. + * @startup: Called when a client requests the chan. The controller + * could ask clients for additional parameters of communication + * to be provided via client's chan_data. This call may + * block. After this call the Controller must forward any + * data received on the chan by calling mbox_chan_received_data. + * The controller may do stuff that need to sleep. + * @shutdown: Called when a client relinquishes control of a chan. + * This call may block too. The controller must not forward + * any received data anymore. + * The controller may do stuff that need to sleep. + * @last_tx_done: If the controller sets 'txdone_poll', the API calls + * this to poll status of last TX. The controller must + * give priority to IRQ method over polling and never + * set both txdone_poll and txdone_irq. Only in polling + * mode 'send_data' is expected to return -EBUSY. + * The controller may do stuff that need to sleep/block. + * Used only if txdone_poll:=true && txdone_irq:=false + * @peek_data: Atomic check for any received data. Return true if controller + * has some data to push to the client. False otherwise. + */ +struct mbox_chan_ops { + int (*send_data)(struct mbox_chan *chan, void *data); + int (*startup)(struct mbox_chan *chan); + void (*shutdown)(struct mbox_chan *chan); + bool (*last_tx_done)(struct mbox_chan *chan); + bool (*peek_data)(struct mbox_chan *chan); +}; + +/** + * struct mbox_controller - Controller of a class of communication channels + * @dev: Device backing this controller + * @ops: Operators that work on each communication chan + * @chans: Array of channels + * @num_chans: Number of channels in the 'chans' array. + * @txdone_irq: Indicates if the controller can report to API when + * the last transmitted data was read by the remote. + * Eg, if it has some TX ACK irq. + * @txdone_poll: If the controller can read but not report the TX + * done. Ex, some register shows the TX status but + * no interrupt rises. Ignored if 'txdone_irq' is set. + * @txpoll_period: If 'txdone_poll' is in effect, the API polls for + * last TX's status after these many millisecs + * @of_xlate: Controller driver specific mapping of channel via DT + * @poll: API private. Used to poll for TXDONE on all channels. + * @node: API private. To hook into list of controllers. + */ +struct mbox_controller { + struct device *dev; + struct mbox_chan_ops *ops; + struct mbox_chan *chans; + int num_chans; + bool txdone_irq; + bool txdone_poll; + unsigned txpoll_period; + struct mbox_chan *(*of_xlate)(struct mbox_controller *mbox, + const struct of_phandle_args *sp); + /* Internal to API */ + struct timer_list poll; + struct list_head node; +}; + +/* + * The length of circular buffer for queuing messages from a client. + * 'msg_count' tracks the number of buffered messages while 'msg_free' + * is the index where the next message would be buffered. + * We shouldn't need it too big because every transfer is interrupt + * triggered and if we have lots of data to transfer, the interrupt + * latencies are going to be the bottleneck, not the buffer length. + * Besides, mbox_send_message could be called from atomic context and + * the client could also queue another message from the notifier 'tx_done' + * of the last transfer done. + * REVISIT: If too many platforms see the "Try increasing MBOX_TX_QUEUE_LEN" + * print, it needs to be taken from config option or somesuch. + */ +#define MBOX_TX_QUEUE_LEN 20 + +/** + * struct mbox_chan - s/w representation of a communication chan + * @mbox: Pointer to the parent/provider of this channel + * @txdone_method: Way to detect TXDone chosen by the API + * @cl: Pointer to the current owner of this channel + * @tx_complete: Transmission completion + * @active_req: Currently active request hook + * @msg_count: No. of mssg currently queued + * @msg_free: Index of next available mssg slot + * @msg_data: Hook for data packet + * @lock: Serialise access to the channel + * @con_priv: Hook for controller driver to attach private data + */ +struct mbox_chan { + struct mbox_controller *mbox; + unsigned txdone_method; + struct mbox_client *cl; + struct completion tx_complete; + void *active_req; + unsigned msg_count, msg_free; + void *msg_data[MBOX_TX_QUEUE_LEN]; + spinlock_t lock; /* Serialise access to the channel */ + void *con_priv; +}; + +int mbox_controller_register(struct mbox_controller *mbox); /* can sleep */ +void mbox_controller_unregister(struct mbox_controller *mbox); /* can sleep */ +void mbox_chan_received_data(struct mbox_chan *chan, void *data); /* atomic */ +void mbox_chan_txdone(struct mbox_chan *chan, int r); /* atomic */ + +#endif /* __MAILBOX_CONTROLLER_H */ diff --git a/include/linux/mailbox.h b/include/linux/pl320-ipc.h index 5161f63ec1c..5161f63ec1c 100644 --- a/include/linux/mailbox.h +++ b/include/linux/pl320-ipc.h |